Re: [SR-Users] call forking using dbaliases not working for un-NATed clients

On 19.09.2012 12:24, Yufei Tao wrote: That's strange. For NATed clients, $du must contain the 'received' URI. Otherwise they can not be contacted as $ru contains the private IP address. It seems db_lookup() creates multiple branches. Is lookup() only finding 1 contact in table or multiple contacts? regards Klaus > Yufei > > On 18/09/12 18:49, Klaus Darilion wrote: >> I suspect that the branch route is first executed for the NATed >> client. Then the 'received' column is used as destination URI. When >> executing the branch route again, the destination URI is still the >> value from the previous branch, and lookup() will not overwrite is as >> 'received' is not available. Then Kamailio sends the INVITE again to >> the first client. >> >> You can try to set $du to Null before lookup(). ($du=null or >> $du=$null, not sure what the correct syntax is). >> >> Another workaround is to use fix_nated_register() for every client >> (the pragmatic and more secure approach). >> >> regards >> Klaus >> >> On 18.09.2012 15:16, Yufei Tao wrote: >>> Hi >>> >>> I have a strange problem on forking calls to a group of users. For >>> example I have two users y2 and y3 in dbaliases, both with >>> alias_username 'group'. And y2 and y3 both registers with Kamailio >>> fine. >>> When I make a call to 'group' from a third client y1, what my >>> kamailio.cfg does is: do an alias_db_lookup("dbaliases"), and goes to >>> BRANCH_ALIASDB, where a lookup location will be done for each of the >>> username resulting from lookup of dbaliases, something like this: >>> >>> y1--INVITE 'group'-->lookup >>> dbaliase-->[BRANCH_ALIASDB]--->'y2'-->lookup >>> location---? >>> >>> | |-->relay >>> >>> ---->[BRANCH_ALIASDB]--->'y3'-->lookup >>> location---- >>> >>> The all works well as long as all clients are NAT'ed. However when >>> they >>> are not NAT'ed, e.g. all on the same LAN with Kamailio, the call only >>> goes to one of the group members, e.g. y2 only. When checking the log, >>> it seemed to have done the dbaliases lookup fine, and each location >>> lookup successfully. But Kamailio only relayed y2's IP, e.g. to the >>> client, while y3's to itself. >>> >>> When comparing the location table when clients are NAT'ed or not, I >>> find >>> that the 'received' column is only populated when I do >>> fix_nated_register. And group calls only works when 'received' >>> column is >>> populated. That explains why when clients are NAT'ed group calls work, >>> as I only do fix_nated_register if nat_uac_test returns true. >>> >>> But if this is the only reason, if two clients register using the same >>> username, e.g. both as y3, and when 'received' column of location >>> table >>> is empty (no fix_nated_register done), I would expect a call to y3 >>> should also only make 1 client ring. But in fact both of them rang! >>> The >>> flow is like: >>> >>> y1--INVITE 'y3'-->lookup location for 'y3'----> IP of 1st client >>> registered as 'y3' >>> | >>> ---> IP of 2nd client >>> registered as 'y3' >>> >>> While a call to 'group' (thus dbaliases lookup took place) under such >>> un-NAT'ed set up made only 1 client ring. >>> >>> So I can make it work by always doing fix_nated_register. But I'm not >>> clear about these things: >>> - why does a lookup of dbaliases before lookup of location make such >>> difference? >>> - does lookup location work differently depending on whether it is >>> called from trunk or from a route called from a branch route? >>> >>> >>> Following is relevant parts from my config file: >>> >>> ############################################################# >>> route[LOCATION] >>> { >>> if ( alias_db_lookup("dbaliases") ) >>> { >>> t_on_branch("BRANCH_ALIASDB"); # in >>> branch_route[BRANCH_ALIASDB], >>> # call another route that >>> looks up >>> location, >>> # if not existent, call drop() >>> >>> } >>> else >>> { >>> xlog("L_DBG","LOCATION: not alias - go to lookup location >>> trunk\n"); >>> route(LOCATION_TRUNK); # normal look up location and sending of >>> 404 etc >>> } >>> >>> ... ... >>> } >>> ############################################################# >>> branch_route[BRANCH_ALIASDB] >>> { >>> xlog("L_DBG", "BRANCH_ALIASDB: $fU@$fd -> $rU@$rd; >>> Method:$rm\n"); >>> route(LOCATION_BRANCH); >>> } >>> >>> route[LOCATION_BRANCH] >>> { >>> if (!lookup("location")) >>> { >>> # Drop this branch - it's going nowhere >>> drop(); >>> } >>> } >>> ############################################################# >>> route[RELAY] { >>> xlog("L_DBG","RELAY: method=$rm, callid=$ci, cseq=$cs\n"); >>> >>> >>> #!ifdef WITH_NAT >>> if (check_route_param("nat=yes")) { >>> setbflag(FLB_NATB); >>> } >>> if (isflagset(FLT_NATS) || isbflagset(FLB_NATB)) { >>> xlog("L_DBG", "RELAY: about to call RTPPROXY\n"); >>> route(RTPPROXY); >>> } >>> #!endif >>> >>> /* example how to enable some additional event routes */ >>> if (is_method("INVITE")) { >>> t_on_reply("REPLY_ONE"); >>> t_on_failure("FAIL_ONE"); >>> } >>> >>> if (!t_relay()) { >>> sl_reply_error(); >>> } >>> >>> exit; >>> } >>> >>> ############################################################ >>> route[NAT] { >>> #!ifdef WITH_NAT >>> xlog("L_DBG","NAT: method=$rm, callid=$ci, cseq=$cs\n"); >>> >>> force_rport(); >>> if (nat_uac_test("2")) { >>> if (method=="REGISTER") { >>> fix_nated_register(); >>> xlog("L_DBG","NAT: Just done fix_nated_register in >>> REGISTER >>> message in NAT route\n"); >>> } else { >>> xlog("L_DBG","NAT: fix_nated_contact\n"); >>> fix_nated_contact(); >>> } >>> setflag(FLT_NATS); >>> } >>> >>> # setflag(FLT_NATS); ## -- YT: set NAT flag for all, so will force >>> media relay >>> #!endif >>> return; >>> } >>> >>> ############################################################# >>> And in the main route, route LOCATION and RELAY are the last two >>> routes: >>> route { >>> ... >>> route(NAT); >>> >>> ... ... >>> >>> # user location service >>> route(LOCATION); >>> >>> route(RELAY); >>> } >>> >>> Hope I have made it clear. Thanks very much! >>> >>> Yufei >>> -- >>> Yufei Tao >>> Red Embedded